Aerosol starch composition

ABSTRACT

An aerosol starch composition consists essentially of 5 to 30 wt % of a propellant and 70 to 95 wt % of a liquid composition consisting essentially of 2 to 10 wt % of a modified starch, 0.1 to 2 wt % of a poorly water-soluble polyalkylene glycol or derivative thereof and the balance is water.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to an aerosol starch composition having agood sprayability.

2. Description of Prior Arts

Starches used in ordinary households are divided into concentrate typestarches which are used in the form of a water dilution into whichclothes and the like are dipped and aerosol type starches which aredirectly sprayed onto cloths and the like.

When a concentrate type starch is used, after a cloth has beensufficiently impregnated with the starch solution and dried, water isscattered on the cloth by a sprayer and the cloth is ironed. In thiscase, the starch is not left on the surface of the cloth in the form ofa white film. However, in case of an aerosol type starch, ironing isoften conducted before the sprayed paste composition is sufficientlyimpregnated into a cloth, and in this case, a white solid starch is leftlocally on the surface of the cloth, resulting in a poor appearance andother troubles, especially when the cloth is a colored or patternedcloth.

SUMMARY OF INVENTION

The present invention has been completed as a result of research worksmade with a view to overcoming this defect of aerosol type starches.Namely, the present invention is based on the finding that a starchformed by adding a poorly water-soluble polyalkylene glycol orderivative thereof to a specific starch solution and filling theresulting composition into an aerosol can has a good sprayability and itdoes not leave a white residue on the surface of a cloth even when thecloth is ironed.

More specifically, in accordance with the present invention, there isprovided an aerosol starch composition comprising 2 to 10% of a modifiedstarch selected from the group consisting of hydroxyalkylated starcheshaving hydroxyalkyl groups of 2 to 4 carbon atoms and carboxyalkylatedstarches having carboxyalkyl groups of 2 to 4 carbon atoms (having aviscosity of 5 to 30 cp as measured with respect to a 5% aqueoussolution at 20° C.) and 0.1 to 2% of a poorly water-soluble polyalkyleneglycol or derivative thereof selected from the group consisting ofpolypropylene glycol (molecular weight 1,000 to 20,000) and polybutyleneglycol (molecular weight 500 to 10,000) and propylene oxide or butyleneoxide adduct to polyhydric alcohols having 2 to 6 carbon atoms(molecular weight 1,500-10,000) (having a water-solubility lower than 2%at 25° C.).

As the low viscosity modified starch that is used as a polymeric starchbase in the present invention, there can be mentioned, for example,hydroxyalkylated starches and carboxyalkylated starches. Modifiedstarches prepared by reacting an alkylene oxide having 2 to 4 carbonatoms or a halogenated carboxylic acid having 2 to 4 carbon atoms with aslurry containing an alkali material and a starch and treating thereaction product with an oxidizing agent such as hydrogen peroxide,sodium hypochlorite or the like to reduce the viscosity are convenientlyused in the present invention. As preferred examples of the modifiedstarch to be used in the present invention, there can be mentionedhydroxyalkylated starches having a hydroxyalkyl group having 2 to 3carbon atoms, that is hydroxyethylated starch and hydroxypropylatedstarch. The low viscosity modified starch that is used in the presentinvention has a viscosity of 5 to 30 cp, preferably 8 to 15 cp, asmeasured with respect to a 5% aqueous solution at 20° C. When theviscosity is too low, a good stiffness cannot be given to a cloth. Incontrast, if the viscosity is too high, a good spray state cannot beattained.

When a poorly water-soluble polyalkylene glycol or derivative thereof isadded to a solution of the above-mentioned modified starch, a very goodsprayability can be attained.

As the polyalkylene glycol, there can be mentioned, for example,polypropylene glycol (molecular weight 1,000-20,000, preferably1,500-10,000) and polybutylene glycol (molecular weight 500-10,000), andas the polyalkylene glycol derivative, there can be mentioned, forexample, propylene oxide or butylene oxide adducts to polyhydricalcohols having 2 to 6 carbon atoms (molecular weight 1,500-10,000,preferably 3,000-10,000). As the polyhydric alcohol having 2 to 6 carbonatoms, there can be mentioned, for example, ethylene glycol, propyleneglycol, diethylene glycol, glycerin, sorbitol and mannitol. Among them,the use of polypropylene glycol or propylene oxide adduct to glycerineis especially preferred in the present invention. By the term "poorlywater-soluble" is meant that the water solubility is not more than 2%,especially not more than 0.1%, as measured at 25° C.

In the present invention, the poorly water-soluble polyalkylene glycolor derivative thereof is used in an amount of 0.1 to 2.0%, preferably0.2 to 1%.

The poorly water-soluble polyalkylene glycol or derivative thereof isnot completely dissolved in an aqueous starch solution, and therefore,it is dissolved also in the phase of liquefied propane or a mixturethereof with butane as a propellant.

According to this invention, an aerosol starch composition consistsessentially of 5 to 30 wt %, preferably 7 to 20 wt %, of a propellantand 70 to 95 wt %, preferably 80 to 93 wt %, of a liquid compositionconsisting essentially of 2 to 10 wt % of a modified starch, 0.1 to 2 wt% of a poorly water-soluble polyalkylene glycol or derivative thereofand the balance is water. As the propellant, there may be used LPG(liquid petroleum gas) such as one mainly comprising propane or butane.An aerosol starch composition of this invention can be effectivelysealed in a container at a pressure of 2 to 4 atm, preferably 2.5 to 3.5atm.

The composition of the present invention may further comprise anon-ionic surface active agent, an ironing lubricant such aspolyethylene glycol or silicone, a perfume, a fluorescent dye, otheradditive and a solvent such as ethyl alcohol according to need.

The present invention will now be described by reference to thefollowing Examples.

EXAMPLE 1

A 5% aqueous solution of a hydroxypropylated starch (having a degree ofsubstitution of 0.12 and a viscosity of 10 cp as measured with a 5%aqueous solution) was prepared and filled in an aerosol can, andliquefied propane (having an inner pressure of 3.1 Kg) was filled in thecan at an aqueous starch solution/liquefied propane weight ratio of70/30 to form an aerosol starch (hereinafter referred to as "aerosolstarch A"). When this aerosol starch A was sprayed on a black-dyedcotton cloth, foams were observed. The cloth was allowed to stand stillfor 1 minute after spraying and was then ironed by using an automaticiron, Model HIA-412 manufactured by Toshiba, while setting the dial to"cotton". The starch residue was observed here and there on the surfaceof the cloth, and the appearance of the cloth was bad.

Separately, 0.5% of polypropylene glycol (having a molecular weight of4,000 and a water solubiltity lower than 0.1%) was added to the aboveaqueous starch solution, and an aerosol starch (hereinafter referred toas "aerosol starch B") was prepared in the same manner as describedabove. When the aerosol starch B was sprayed to a cotton cloth, foamswere scarcely observed, and scarcely any white residue was left on thesurface of the cloth after ironing.

The foaming property was quantitatively determined in the followingmanner. Namely, a 100 cc capacity graduated cylinder equipped with aplug was charged with 50 cc of the starch solution, and the cylinder wasstrongly shaken in the vertical direction. Immediately, the amount offoam was measured, and also the time required for the foam to disappearwas measured. Obtained results are shown below.

    ______________________________________                                                    Amount      Foam Disappearing                                     Sample      Foam        Time (seconds)                                        ______________________________________                                        A           5.8         10                                                    B           0.7         below 1                                               ______________________________________                                    

EXAMPLE 2

A spray starch packed in an aerosol can was prepared in the same manneras described in Example 1 according to the following formulation byusing polyvinyl alcohol (B-05 manufactured by Denki Kagaku Kogyo) orhydroxypropylated starch (having a degree of substitution of 0.17 and aviscosity of 9.5 cp as measured with respect to a 5% aqueous solution).In the case of the starch of the polyvinyl alcohol type, foaming wascaused on the surface of a cloth on spraying, but when thehydroxypropylated starch was used, foaming was hardly caused.

    ______________________________________                                        Polyvinyl alcohol or hydroxypropylated                                                                  5%                                                  starch                                                                        Polyethylene glycol (molecular                                                                          3%                                                  weight = 400)                                                                 Silicone emulsion (silicone of 6000                                                                     0.5%                                                centistokes, effective content of 25%)                                        Diethylene glycol-propylene oxide adduct                                                                0.5%                                                Water                     balance                                             ______________________________________                                    

EXAMPLE 3

Spray starches packed in aerosol cans were prepared in the same manneras described in Example 1 according to the following formulation byusing the additives indicated below, and each starch was tested withrespect to the formation of the residue on the surface of a black clothand the degree of foaming on the cloth. Further, the amount of foam andthe foam disappearing time were determined in the same manner asdescribed in Example 1. Obtained results are shown in the Table givenbelow.

    ______________________________________                                        Hydroxyethylated starch (having a degree of                                                                4%                                               substitution of 0.14 and a viscosity of 12 cp                                 as measured with respect to a 5% aqueous solution)                            Partially esterified styrene-maleic anhydride                                                              1%                                               copolymer (having a degree of esterification                                  of 0.5)                                                                       Polyethylene glycol (having a molecular                                                                    3%                                               weight of 200)                                                                Silicone emulsion (silicone of 6000 centistokes,                                                           0.5%                                             effective content of 25%)                                                     Additive (indicated in the Table given below)                                                              0.5%                                             Water                       91.0%                                             ______________________________________                                    

                                      Table                                       __________________________________________________________________________                Water              Foam Dis-                                              Molec-                                                                            Solu-                                                                             Foaming                                                                            Residue                                                                            Amount                                                                             Appearing                                              ular                                                                              bility                                                                            on   on   (cc) of                                                                            Time                                           Additive                                                                              Weight                                                                            (%) Cloth*                                                                             Cloth**                                                                            Foams                                                                              (seconds)                                      __________________________________________________________________________    Polypropylene                                                                         200 ∞                                                                           ++   +    5.0  23                                             glycol                                                                        "       400 ∞                                                                           ++   +    4.3  20                                             "       750 3   ++   +    4.2  8                                              "       1200                                                                              2   -    -    2.8  <1                                             "       2000                                                                              <0.1                                                                              -    -    0.6  <1                                             "       4000                                                                              <0.1                                                                              -    -    0.5  <1                                             Glycerin                                                                              92  ∞                                                                           ++   +    5.5  20                                             Glycerin-                                                                     propylene                                                                             600 >100                                                                              ++   +    5.3  12                                             oxide adduct                                                                  "       1000                                                                              >30 ++   +    4.8  18                                             "       2000                                                                              1   -    -    2.3  <1                                             "       3000                                                                              0.1 -    -    1.8  <1                                             "       4000                                                                              <0.1                                                                              -    -    2.0  <1                                             Polyethylene                                                                          400 ∞                                                                           ++   +    6.0  26                                             glycol                                                                        "       2000                                                                              ∞                                                                           ++   +    6.3  28                                             Silicone                                                                      emulsion                                                                              -   -   +    +    3.1  1                                              (viscosity                                                                    of silicone                                                                   per se = 1000                                                                 centistokes)                                                                  not added                                                                             -   -   ++   +    6.2  25                                             __________________________________________________________________________     Notes                                                                         ++conspicuous                                                                 +relatively conspicuous                                                       -hardly observed                                                         

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
 1. In a pressurized container having a discharge valve and charged with a self-propelling composition which can be dispensed in an aerosol mist form when said discharge valve is opened, the improvement which comprises:said composition consists essentially of (A) 5 to 30 wt % of a liquified normally gaseous propellant effective for discharging an aerosol of the composition when said discharge valve is opened and (B) 70 to 95 wt % of a liquid composition consisting essentially of(i) 2 to 10 wt %, based on the weight of (B), of a modified starch selected from the group consisting of hydroxyalkylated starch containing hydroxyalkyl groups having 2 to 4 carbon atoms and carboxyalkylated starch containing carboxyalkyl groups having 2 to 4 carbon atoms, wherein said modified starch has the property that a 5% aqueous solution of said modified starch has a viscosity of 5 to 30 cp, at 20° C., (ii) 0.1 to 2 wt %, based on the weight of (B), of a material selected from the group consisting of polypropylene glycol having a molecular weight of 1,000 to 20,000, polybutylene glycol having a molecular weight of 500 to 10,000, an adduct of propylene oxide to a polyhydric alcohol having from 2 to 6 carbon atoms wherein said propylene oxide adduct has a molecular weight of 1,500 to 10,000 and an adduct of butylene oxide to a polyhydric alcohol having 2 to 6 carbon atoms wherein said butylene oxide adduct has a molecular weight of 1,500 to 10,000, said material having a water solubility of not more than 2%, at 25° C., and (iii) the balance is water.
 2. An aerosol starch composition as claimed in claim 1, in which said modified starch is a hydroxyalkylated starch containing a hydroxyalkyl group having 2 or 3 carbon atoms.
 3. An aerosol starch composition as claimed in claim 1, in which the amount of said material is from 0.2 to 1 wt %.
 4. An aerosol starch composition as claimed in claim 1, in which the water solubility of said material is not more than 0.1%, at 25° C.
 5. An aerosol starch composition as claimed in claim 1, in which said material is polypropylene glycol having a molecular weight of 1,000 to 20,000.
 6. An aerosol starch composition as claimed in claim 1, in which said material is a glycerin-propylene oxide adduct having a molecular weight of 1,500 to 10,000.
 7. An aerosol starch composition as claimed in claim 1, in which said propellant is LPG. 